1. Field of the Invention
This invention relates to a system for and method of determining the allocation of a resource among a series of demands which require an allocation of the resource, thereby optimizing the probability of successfully overcoming each of the series of demands.
2. Description of the Prior Art
An example of a situation where such demands are present is where a pilot of an aircraft assigned to a mission to a target passing over enemy territory in which there is located a series of threats in the form of ground based missile or gun systems has at its disposal a limited defense suppression resource to defend the aircraft against the enemy threats. It appears that the natural instinct of the pilot when threatened by a missile or gun system is to deploy his resources in the form of chaff, ECM capability etc., against each individual threat as is necessary to make the possibility of destruction of the aircraft by that threat very small. In a case where the aircraft has an infinite amount of resource units, this would not adversely affect mission success, but where, as is usual, the aircraft has only a finite number of resource units, and the aircraft will be subject to many threats during the mission, the pilot in ensuring that the aircraft survives, say, the first threat, in fact may dramatically reduce the probability of the whole mission success even though he maximises the probability of surviving the first threat.
In another instance, the resource could be continuous, in the form of radar-jamming apparatus. In this instance, the pilot of the aircraft needs to know how to allocate the jamming power both in direction and across the frequency band width of the apparatus. For example, for optimum probability of mission success, it may be that the jamming power should be spread evenly across the frequency band width, or, more likely, that a relatively high jamming power be generated at a few isolated frequencies. It will be appreciated that the output waveband may be envisaged as a series of incremental demands.
In yet another instance, the resource may be the path itself taken by the pilot between two or more missile sites located on either side of the mission path. Here, each missile site will have an associated series of threat contours surrounding it, which may or may not be the same for each site. The pilot of the aircraft needs to know the optimum path between the sites having regard to the threat contours of each missile site.
The term "resource" is therefore used in this Specification to denote a variable which may be controlled to enhance the probability of successfully overcoming a threat, that is to say, a demand on that resource. For example, it could be a geographical path, a fuel supply, or a continuous radar jammer, with a limited amount of power available to jam frequencies which can be selected by the operator. In a non-military environment, it could be an annual budget which must be allocated between various commercial departments.
In this Specification, the term "demand success probability data" is used to describe data indicating the respective probability of successfully overcoming a given demand for each amount of resource which may be allocated to it. Thus, in the case of a single demand, the success probability data lists the function P.sub.si (.chi.) for 0&lt;.chi.&lt;X, where P.sub.si (.chi.) is the probability of successfully overcoming the demand i when proportion x of the resource is allocated to it. In the case of a combination of two or more demands, the term "optimum success probability data" is used to describe data indicating the respective optimum probability of successfully overcoming a combination of two or more selected demands, for each available allocation of resource to the combination. Thus, the optimum success probability data lists P.sub.SC (.chi.) for 0&lt;.chi.&lt;X where P.sub.SC (.chi.) is the maximum probability of successfully overcoming the combination, that is assuming that resource .chi. is optimally distributed among the demands of the combination. The term "optimum distribution data" is used to describe data indicating for each available allocation of resource between a combination of demands the respective distribution between the demands which results in the optimum probability of success.